vocab Flashcards
What is stats
The study of variability
What is variability
Differences, how things differ
2 branches of AP stats
Inferential and descriptive
What are descriptive stats?
tell what you got describing the data
What is inferential stats
look at the data and use that to say stuff about the big picture
Compare descriptive and inferential
descriptive explains about the data you have inferential uses a small portion to explain the big population
what is data
any collected infromation
what is population?
the group you are interested in
what is a sample?
a subset of the entire pop.
compare population and sample
pop is generally large where samples are subsets of these large groups
compare data and statistics
data is each little bit collected from the individual where statistic is a summary of that data if only a few samples from the population was collected exp: the mean of a data set
compare data and parameters
data is each little bit collected from the individual parameters are if we collected data from every person
What is a parameter
a numerical summary of a population
what is a statistic
a numerical summary of a sample
We are curious about the average wait time at Dunkin donuts drive through in your neighborhood. You randomly sample care one afternoon and find the average wait time is 3.2 minutes. what is the population parameter? what is the statistic? what is the parameter of interest? what is the data?
The parameter is the true average wait time and dunkin. this is a number you dont have and will never know. The statistic is 3.2 minutes. It is the average of the data you collected. The parameter of interest is the same thing as the population parameter. in this case, it is the true average wait time of all cars. the data is the wait time of each individual car, So the would be like “3.8 min, 2.2 min, .8 min, 3 min”. You take that data and find the average, that average is called a statistic, and you use that to make an inference about the true parameter.
Compare data-statistic-parameter using a categorical example.
Data are individual measures, Statistics and parameters are summaries.
Compare data-statistic-parameter using quantitative example.
Data are individual measures. Statistics and parameters are summaries of the data collected
what is a census?
information from every member in a population
does a census make sense?
only is small populations
what is the difference between a parameter and a statistic
both are summarizing bigger groups of data but parameters come from whole populations and statistics come from samples
if i take a random sample of 20 hamburgers from five guys and count the number of pickles on a bunch of them and one of them had 9 pickles the the number 9 from that burger would be called a?
datum or data value
if i take a random sample of 20 hamburgers from five guys and count the number of pickles on a bunch of them and the average number of pickles was 9.5 then 9.5 is considered a?
statistic
if i take a random sample of 20 hamburgers from five guys and count the number of pickles on a bunch of them and i do this bc i want to know the true average of pickles on a burger the true average number of pickles is considered a?
parameter a one number summary of the population
what is the difference between sample and census?
sample is information from a small group of the population where census is information from the entire population.
use population, paramte, census, sample, data, statistics, inference and population of inference in one sentence
I was curios about a population parameter, but a census was too costly so i decided to choose a sample, collect some data, calculate a statistic and use that statistic to make an inference about the population parameter AKA population of interest
if you are tasting soup the the flaour of each individual thing in the spoon is the _____, the entire spoon is a ____. the flouvor of all of that stuff together is like the _____ and you use that to _____ about the flavour of the entire pot of soup, which would be the _____
Data, Sample. Statistic, Make and inference, Parameter
what are random variables?
random people chosen from a list then the hair and eye color, weight and height are random variables
difference between quantitative and categorical/Qualitative
Quantitative is using numbers where categorical is using qualities or categories
What is the difference between quantitative and categorical/Qualitative
quantitative would use numbers where categorical would use words like eye color or skin tone
Difference between discrete and continuous
discrete uses whole number where continuous uses decimal points and fractions
what is a quantitative variable
a numerical variable
what is a categorical variable
a variable that is categorized
another name for categorical
qualitative
what is quantitative data?
actual numbers gathered from a data set
what is categorical data?
the actual individual category
what is a random sample
A sample the a chosen by true randomness
what is frequency
How often something appears
data or datum?
datum is singular data is plural
what is a frequency distribution
a table or chart that shows how often certain values appear
what is meant by relative frequency
the percent of of time something appears
how do you find relative frequency?
divide frequency by total
what is meant by cumulative frequency?
add up the frequencies as you go
what is relative cumulative frequency
the added up percentages
difference between bar chart and histogram
bar chart are categorical data histograms or quantitative data
what is mean?
old average we used to calculate (scrub)
difference between population mean and sample mean
population mean is parameter sample mean is statistic
what symbols do we use for population mean and sample mean?
Mu for pop x bar for sample
how do you remember the difference between mean and median when looking at a histogram
mean is a balancing point median splits it in half
what is the median?
the middle most number
what is mode?
the most common number
when do we use mode?
with categorical variables
why don’t we always use mean?
it is not resilient its a little bitch
When we say “the average teen” are we using mean median or mode?
height=mean
parental income=median
music preference=mode
what is a example of the mean changing but not the median
8 peoples wallets 1, 2, 2, 5, 5, 8, 8, 9 mean is 5 so is median
8 peoples wallets 1, 2, 2, 5, 5, 8, 8, 9000 now mean is over 1000 but median is still 5
How are the three m’s on a left skewered histogram
Mean median mode
how are the three m’s on a right skewered histogram
opposite mode median mean
who chases the tail?
the mean chases the tail the mean chases the tail high-ho the derry-oh the mean chases the tail… and outliers
